There are numerous synonyms for the phrase "a while" that you can use in your writing to express the idea of a measure of time. Some of the most common alternatives include "a short time," "a bit," "a few moments," "a spell," "a stretch," "a tick," "a minute," and "a moment." You may also use "for a time," "in a moment," "temporarily," or "briefly" to indicate a short span of time. These synonyms are especially useful in writing, as they can help you avoid repetition and keep your sentences sounding fresh and varied. So, choose your synonym wisely and add it to your writing to convey the appropriate meaning effortlessly.